Self-propelled robotic pool cleaners include one or more drive motors to move or otherwise propel the cleaner over a surface of a pool being cleaned. The movement of the cleaner can be random or preferably is in accordance with a predetermined cleaning pattern. An electronic controller with memory can be provided on board the robotic pool cleaner for storing and executing cleaning programs, as well as other information to enable efficient cleaning of the pool.
The pool cleaner receives power from a remote power supply via a floating power cable having a pair of conductors. Typically, the power supply is configured to be portable so that an end-user can easily move the power supply from a remote storage area to a location in close proximity to the pool so that the cleaner is free to move about without undue drag exerted by the power cable. As a further convenience, many pool cleaner manufacturers provide a handcart which is configured to transport the cleaner, the cable and the power supply to and from the pool.
The remote power supply includes an internal power transformer and/or switching circuitry to enable operation from a conventional wall outlet or socket (e.g., 120 VAC (alternating current voltage) which is readily available at the end-user's residence or other facility. The transformer and/or switching circuitry converts the AC power from the conventional wall socket to a direct current voltage (VDC) output at a relatively lower voltage that is sufficient to operate the drive and/or pump motor(s) and control the pool cleaner during its cleaning operation.
The pool cleaner power cable is typically fabricated from two wire conductors having sufficient length to at least enable the cleaner to move over the entire bottom surface of the pool. The conductors have a protective covering that is typically fabricated from a foamed polymeric material that is buoyant and enables the cable to float as the submerged cleaner moves over the bottom and, optionally, the sidewall surfaces of the pool.
The power supply provides electrical power to drive one or more motors of the cleaner which propel the cleaner over the pool surfaces. For example, the one or more motors can rotate the wheels, roller brushes, and/or tracks of the cleaner via a transmission assembly. Alternatively, a pump motor having one or more propellers can be used to discharge a pressurized stream of filtered water in the form of a water jet that also propels the cleaner in a direction opposite the water jet. Some of the electrical power supplied by the power cable can also be directed to an on-board controller that includes a microcontroller, logic circuitry and/or programs to control the movement of the cleaner.
External or remote power supplies of the prior art have limited control functions over the pool cleaner, such as providing power on and off, reversing polarity to the drive motor/water pump, timers, and the like. Typically, the primary control of current pool cleaners has been facilitated by on-board microcontrollers that are programmed to control the cleaning operations in the pool.
Further, most robotic pool cleaners do not have their own power sources/supplies and the power cable is typically a two-wire cable, thereby limiting the extent of communications between the power supply and the pool cleaner. One option is to send communication signals over the two-wire cable to the cleaner's microcontroller in the form of pulsed power signals. However, such pulsed power signals can cause the drive motor(s), cleaner logic and support circuitry of the cleaner to intermittently lose power, as well as lose their ground reference in the cleaner.
A three-wire cable can be utilized to provide full-duplex communications in order to send communication signals without the power interruptions and ground reference losses; however, such three-conductor cables are significantly more expensive than two-wire power cables, and therefor are usually cost prohibitive to implement.
A robotic pool cleaner typically includes one or more cleaning programs stored in the memory of its on-board microcontroller. The microcontroller includes one or more sensors such as a tilt switch or accelerometer that sends a signal to the microcontroller to indicate when the cleaner is climbing a sidewall of the pool. The microcontroller can operate with internal or external timers or other sensors for ascending and descending the sidewall of the pool. Providing control operations on the cleaner adds complexity and can increase the costs to manufacture the cleaner.
It would therefore be desirable to transfer various cleaner control functions from on board the pool cleaner to the external or remote power supply. In particular, it would be desirable to provide communications over a two-wire cable between the power supply and the cleaner. It also would be desirable to enable control of the pool cleaner programming from the control circuitry of the remote power supply. As well, it would be desirable to establish communications between a remote power supply and a cleaner motor having circuitry with one or more orientation sensors. It would be also desirable to transfer greater control of the cleaning operations of the cleaner to the power supply in order to reduce programming costs associated with each cleaner. As well, it would be desirable to transfer greater control of cleaning operations across different models of the cleaner so that a single power supply model can be programmed to operate “universally” for various pool cleaner models.